BACPAC
BACPAC, or the Berkeley Advanced Chip Performance Calculator, is a software program to explore the effect of changes in IC technology. The use enters a set of fairly fundamental properties of the technology and the program estimates the system level performance of an IC built with these assumptions. Previous work in this area can be found in and, but these do not consider many of the effects of deep-sub-micrometre interconnect. BACPAC is based on the work in.
BACPAC uses analytical approximations for system properties such as delay and interconnect requirements. The intent is not absolute accuracy for a given design, but to show trends and effects of technology changes.
Inputs to BACPAC
Interconnect- Number of routing layers
- Pitches
- Resistivity of the wires
- Dielectric constant of the insulators between the layers
- Vdd, also called supply voltage
- Vt, also called threshold voltage
- Gate oxide thickness of the MOS transistors
- Drain current
- Fan-in
- Block design size
- Silicon efficiency
- logic depth
- Rent's exponent
BACPAC outputs
Delay analysis- Chip area
- Maximum clock frequency - how fast the chip can run
- Optimized device sizes - estimated devices sizes to make it run this fast
- Interconnect RC
- Average wirelength
- Ratio of wire delay to gate delay
- Clock frequency with noise
- Newly optimized device sizes for the clock distribution network
- Ratio of wire delay to gate delay
- Wiring capacity
- Wiring requirements,
- Wiring needs for clock distribution
- Wiring needs for the power distribution network
- Total power consumption, divided into sub-categories:
- *Clock
- *I/O
- *memory
- *global wiring
- *logic
- *short-circuit
- *leakage
- Projected yields for excellent, average, and poor process control using a negative binomial yield mode